[Medical and occupational radiation exposure: present situation and countermeasures]

This paper describes the present status and countermeasures for patient dose and occupational exposure in Japan. The patient radiation dose resulting from a large number of diagnostic radiological procedures presents no substantial risk(deterministic and stochastic effects). Nevertheless, some procedures (e.g., interventional radiology: IVR) carry a risk of deterministic effects, such as skin injury. The regulatory dose limit of the occupational dose for most medical workers was not exceeded. Nevertheless, radiation injuries, such as cataracts, to physicians performing IVR have been reported recently, although not many cases. When radiation protection/optimization issues are addressed adequately, medical exposure will decrease without decreasing the diagnostic benefit to the patient. Consequently, decreasing the patient dose will also decrease occupational exposure.